9th Dec to 13th Dec

Project

Current work has been on finishing off the hardware for my development setup. Ideally I don’t want to be move the phone around too much as the serial line is super delicate. I’ve added in a new power button and so moved onto focus on the volume buttons, using an old a5y17lte which I have for parts I removed the volume buttons and found they were simple push buttons on a flex pcb. There are 2 solder pads on each button and after scraping off the plastic coating I was able to solder in wires and another push button.

8th Dec

Project

Only had a short period of time to do any project work today, the busted phone I’m using for development is missing the power button and the volume up buttons. It was getting tedious having to poke my tweezers into the hole to depress the internal mechanism so I lifted off the back plate and then solder 2 wires that led to a simple push button to the two internal pads that I was able to identify using my multimeter. It won’t be possible to do a similar hack for the volume up as there are no exposed pads, I will probably try and use the internal switch mechansim.

6th Dec

Project

Finally managed find some time to work on the a5y17lte - it was time to attempt the very challenging soldering. I’ve replaced my flux which make a big difference and I was able to tin the pads relatively easyily. Using very small enamalled wire and my phone camera on zoom as a sort of microscope I was managed to solder to pads 1 (rx) and 2 (tx) however as I was then gluing the wires down the wire to pad 1 immediately fell off. I’ve tested the tx line and I get serial data out. It does leave me in a prediciment, it would be awesome to have the rx line so I could enter commands over serial but do I risk trying to solder in the wire but could then destroy it all, or do I stick with what I’ve got as serial out is super useful. Currently on the side of sticking.

4th Dec

Project

One of the weird days where I probably had time but nothing got done, bring on the 5th Dec.

Reading

Nothing today

3rd Dec

Project

Finally had a bit a time to get to work on building this test rig. The Samsung A5 I got off ebay is a bit of a disaster, the back plate is pretty much destroyed, the battery is swollen and its missing 2 buttons. I’ve been working with this model for a number of weeks and I’ve learnt that they are super robust, I therefore removed the back case (which was easy as it is shattered) then took off the screwed down cover, removed the battery and replaced it with one from another device.

2nd Dec

Project

I had a busy day of non-DecAdv work so didn’t actually get anything done apart from a ’new’ broken Samsung a5y17lte arrived from ebay, it was listed as not working and must admit its in a pretty terrible shape. I think however I should be able to get it working - the goal of this device is to build a test rig for development, unfortunately the pads on the PCB that break out the serial lines are tiny, i’ve attempted to solder on my other devices and have failed, the last attempt I got the Tx working but then stupidly tried to get Rx attached and ended up lifting the pads, at that point its game over really. So if I can get this device to boot then I’ll try and solder some very thin enamelled wire to the pads and hopefully we’ll have a test rig to start testing kernels. If it doesn’t boot then it’ll be back to ebay to get another one…

December Adventure Plan

1. Read a short story or chapter of a book every day - I’ve got a pile of books that I haven’t got round to read and will possibly get some more as gifts at Christmas - also its nice to balance out a day by reading something.
2. Coding wise the goal is to mainline the Samsung A5 (2017) smart phone, known as a5y17lte. Currently it runs postmarketOS but with the lineage downstream kernel which is 3.8.140, its so old that netfilter doesn’t even seem to work.

1st Dec

Project

So the joy of December Adventure is that its fairly relaxed, so on day 1 the only thing I achieved was signing up for December Adventure.

Update

• STL and scad files published on Printables

Introduction

What happens if you take the big maker/hacker projects from the last few years and combine them into a single device - introducing the Re-Cyber-Lab! The Re-Cyber-Lab is a modified Pelican-based cyber deck which has been blended with a mini homelab rack but using recycled postmarket cell/mobile phones. In its first iteration it is a cluster of 3 Samsung A5 (a5y17lte) phones that are running postmarketOS edge and have usb-c ethernet dongles connected to a network switch. Each phone is held in a 3d printed mounting that sort of looks like a rack. They are all powered by a large usb hub with individual power buttons.

Introduction

Following getting root access on the device and installing a webserver (which hosts this page) it was time to get a bit more complicated and realtime. It felt like the next step was to get some form of chat server working, while I’ve learnt that something like XMPP would be ideal that was a bit too complicated to start with and as I wanted my early internet vibes I went with getting an IRC server running.

A deep dive into the Tenda 4G185 v3 MiFi device with a load of reverse engineering, messing with scripts and finally getting access and running my own code and hosting this website!

Introduction

The Tenda 4G185 v3 is a ‘MiFi’ device - a mobile WiFi Router, it has a 4G/LTE modem and WiFi chip and in between is a small embedded linux system which manages the configuration and bridges the traffic. These MiFi devices seem best placed were you want a dedicated WiFi router rather than hotspotting off your phone or to be used as a backup if your home/business internet connection went down.